Most existing railroad hopper cars adopt box type bottom door structures, and bottom doors are controlled by bottom door opening and closing mechanisms to open and close to achieve an automatic unloading function. Under this structure, the opening, closing and locking of the bottom doors completely depend on the control of the bottom door opening and closing mechanisms. In the case of failure of the bottom door opening and closing mechanisms, the bottom doors are out of effective control and are completely at a free rotation state, and the bottom doors are liable to automatically open due to vibration in a vehicle operation process, resulting in commodity leakage or automatic unloading to affect the traffic safety.
The bottom door opening and closing mechanisms are key components for ensuring the normal unloading of the railroad hopper cars and require convenient opening and closing operations and stable performance, and the existing mechanical impact self-unloading type bottom door opening and closing mechanisms have the above characteristics, thus being widely used on the railroad hopper cars at home and abroad at present. Moreover, corresponding self-locking devices are provided to prevent automatic opening of the bottom doors due to such reasons as vibration and the like or abnormal opening of the bottom doors caused by other factors in a transportation process.
However, the current two-level locking solutions of the hopper cars adopting the mechanical impact self-unloading type bottom door opening and closing mechanisms are based on the locking operation handle principle, which has relatively limited adaptability and cannot meet the requirements of bilaterally opening and closing the bottom doors.